FDA Wants More Data on Gene Therapy for Hemophilia A

Credit: Getty Images.
The Agency requested that the Company provide substantial evidence from its phase 3 study demonstrating durable effect using annualized bleeding rate.

The Food and Drug Administration (FDA) has issued a Complete Response Letter (CRL) to BioMarin regarding the Biologics License Application (BLA) for valoctocogene roxaparvovec for the treatment of hemophilia A in adults. 

Valoctocogene roxaparvovec is an investigational adeno-associated virus (AAV) gene therapy that is administered as a single infusion to produce clotting factor VIII. The BLA submission included interim analysis of a phase 3 study and 3-year phase 1/2 data. Results from the ongoing phase 1/2 study showed that bleed rate control and reduction in factor VIII usage was maintained for a third year following a single administration of valoctocogene roxaparvovec. 

In the CRL, the Agency requested that the Company provide substantial evidence from its phase 3 study demonstrating durable effect using annualized bleeding rate (ABR) as the primary end point. To address these concerns, the Agency is recommending that the Company complete the phase 3 study and submit 2-year follow-up safety and efficacy data on all study patients.

According to the FDA, “the differences between Study 270-201 (phase 1/2) and the phase 3 study limited its ability to rely on the phase 1/2 study to support durability of effect.” The Company intends to meet with the Agency in the coming weeks to discuss the next steps in the approval process.

Related Articles

“We are surprised and disappointed that the FDA introduced new expectations for the first time in the Complete Response Letter,” said Jean-Jacques Bienaimé, Chairman and CEO of BioMarin. “We are confident in valoctocogene roxaparvovec gene therapy and its potential to redefine the treatment paradigm for people with hemophilia A.”

For more information visit biomarin.com.

Reference

BioMarin receives Complete Response Letter (CRL) from FDA for valoctocogene Roxaparvovec gene therapy for severe hemophilia A. https://www.prnewswire.com/news-releases/biomarin-receives-complete-response-letter-crl-from-fda-for-valoctocogene-roxaparvovec-gene-therapy-for-severe-hemophilia-a-301114587.html. Accessed August 19, 2020.